Pornographic images may soon be blocked from computers in Jefferson County public libraries, though the textual content of websites such as those of Playboy and Penthouse may not.

At a library study session Aug. 11, board members weighed several options in regulating Internet content, including doing nothing at all. Other possible choices include blocking only images considered pornographic or blocking pornographic websites in their entirety.

Though library staff and board members seemed to favor filtering images, that process would have several flaws.

“It might block bikini photos as well,” said information-technology director Steve Endicott, noting that filtering software can mistake less objectionable content for porn. “It’s looking at the amount of flesh tone in the photos and trying to determine if it’s pornographic or not. We might get some false positives.”

The library system, which currently blocks content on any computers used by children, began considering changes to its Internet policy after a 17-year-old boy allegedly masturbated in plain sight last month in the Columbine Library while viewing pornography on a computer.

A woman and her 5-year-old son reportedly witnessed the incident and alerted library staff. The teen was later asked to leave the library, and the Sheriff’s Office cited him for indecent exposure.

The incident, which prompted vast media coverage, sparked a wave of public comment, largely in opposition to the library’s policy to leave content on adult-accessed computers unfiltered. Of about 50 e-mails sent to the library’s communications department, 47 opposed the no-filter policy, library spokeswoman Rebecca Winning said.

Consequently, the library board began re-examining its policy in recent weeks, weighing the benefits of unrestricted access against the prospect of more fallout from patrons being exposed to disagreeable images.

Few other libraries in Colorado leave content completely unfiltered, though the Rangeview Library District and Boulder Public Library have policies similar to Jefferson County’s, staff members said.

The library board will likely vote to change the Internet policy at its Aug. 18 meeting. Two board members — Ruth Anna and Lynne Heinekamp — were absent from the Aug. 11 study session.

If the library opts to filter images but not textual content, the websites currently filtered on any computer used by children would continue to be blocked in their entirety, staff members said.

Adult patrons can currently access any legal content on the Internet, including hard-core pornography. Viewing illegal content such as child pornography is forbidden, though no access to such sites is currently blocked, and the libraries do not electronically monitor Internet use.

However, anyone viewing graphic content is required to place polarizing screens over computer monitors at the request of library staff.

“Some 300 pornographic sites are added to the Internet every day … so no system is perfect,” acting program director Cindy Phillipssaid. “There is no way to totally guarantee that you will never see anything offensive.”

The library already owns filtering software that could be used to prevent access to pornography, Phillips said, so no additional costs would burden the system, which is currently facing the prospect of massive budget cuts in 2012, including potential closure of its three smallest branches.

Meanwhile, library staff are apparently divided about whether any filtering should be done, though many are uncomfortable with asking patrons to use the polarizing screens when viewing content deemed either pornographic or violent.

And the issue of viewing exceptionally violent content raised a new concern for the board, library trustee Buddy Douglass said.

“That’s just as offensive to me,” he said, comparing violent content to pornography. “I can’t distinguish between the two.”

Image filtering, which is used by the Douglas County Library system, has been successful in leading to fewer complaints from library patrons, staff said.

If the filters are activated, all computers would filter content, with the exception of a single staff computer in each branch. If patrons object to images or sites being blocked, they could ask to have such content unblocked temporarily for research purposes. Filtering images but not text would continue to provide articles on pornographic sites, and would hopefully keep objections about conservative filtering to a minimum, staff said.

“A person (could) get to the Playboy site and could read the articles, but they can’t see the images,” Phillips said. “Access to the textual content (would be) preserved.”